Supelco® vials are available in a variety of colors, sizes, volume capacities, Vials, screw top, amber glass (vial only), volume 2 mL, amber glass vial, How Pierced PTFE/Silicone Septa Affect GC-MS Experiments. Jan 2, 2006 For the vials with both the crimp-cap and screw-cap closures, no loss was observed for four compounds in 15 hr. It ...